import { useState } from 'react';
import { 
  FiX, 
  FiCheckCircle, 
  FiPlay, 
  FiClock, 
  FiBook, 
  FiStar, 
  FiGlobe, 
  FiAward, 
  FiShield, 
  FiChevronDown, 
  FiChevronUp,
  FiShoppingCart,
  FiLock
} from 'react-icons/fi';
import type { Course } from '../../types/course';

interface CourseModalProps {
  course: Course | null;
  isOpen: boolean;
  isInCart: boolean;
  isTeacherPreview?: boolean;
  onClose: () => void;
  onAddToCart: (course: Course) => void;
  onBuyNow: (course: Course) => void;
}

export const CourseModal: React.FC<CourseModalProps> = ({
  course,
  isOpen,
  isInCart,
  isTeacherPreview = false,
  onClose,
  onAddToCart,
  onBuyNow,
}) => {
  const [expandedModules, setExpandedModules] = useState<Record<string, boolean>>({
    m1: true,
    m2: true,
    m3: true
  });
  const [activeTab, setActiveTab] = useState<'curriculum' | 'instructor' | 'reviews'>('curriculum');
  const [isPlayingVideo, setIsPlayingVideo] = useState(false);

  if (!isOpen || !course) return null;

  const toggleModule = (modId: string) => {
    setExpandedModules((prev) => ({ ...prev, [modId]: !prev[modId] }));
  };

  const discountPercent = Math.round(
    ((course.originalPrice - course.price) / course.originalPrice) * 100
  );

  return (
    <div className="fixed inset-0 z-50 overflow-y-auto bg-slate-950/80 backdrop-blur-md flex items-center justify-center p-2 sm:p-4 animate-in fade-in duration-200">
      
      {/* Modal Container with full Light / Dark Mode support */}
      <div 
        className="relative w-full max-w-5xl transition-colors duration-300 bg-white dark:bg-slate-900 border border-slate-200 dark:border-slate-800 text-slate-900 dark:text-slate-100 rounded-2xl shadow-2xl overflow-hidden my-8 max-h-[92vh] flex flex-col"
        onClick={(e) => e.stopPropagation()}
      >
        
        {/* Top Header Bar */}
        <div className="flex items-center justify-between px-6 py-4 border-b border-slate-200 dark:border-slate-800 bg-slate-50 dark:bg-slate-950/60 sticky top-0 z-20">
          <div className="flex items-center gap-3">
            <span className="text-xs font-semibold px-2.5 py-1 rounded bg-cyan-500/10 text-cyan-600 dark:text-cyan-400 border border-cyan-500/20">
              {course.category}
            </span>
            <span className="text-xs text-slate-500 dark:text-slate-400">• Nivel: {course.level}</span>
            {isTeacherPreview && (
              <span className="text-xs font-bold px-2.5 py-1 rounded bg-amber-500/10 text-amber-600 dark:text-amber-400 border border-amber-500/20 flex items-center gap-1">
                <FiShield /> Vista Previa de Docente
              </span>
            )}
          </div>

          <button
            onClick={onClose}
            className="p-2 rounded-xl text-slate-400 hover:text-slate-900 dark:hover:text-white hover:bg-slate-200 dark:hover:bg-slate-800 transition"
            aria-label="Cerrar modal"
          >
            <FiX className="text-xl" />
          </button>
        </div>

        {/* Modal Body Scrollable */}
        <div className="overflow-y-auto flex-1 p-6 space-y-8">
          
          {/* Top Hero & Video Preview Section */}
          <div className="grid grid-cols-1 lg:grid-cols-12 gap-8">
            
            {/* Main Info */}
            <div className="lg:col-span-7 space-y-4">
              <h2 className="text-2xl sm:text-3xl font-extrabold text-slate-900 dark:text-white leading-tight">
                {course.title}
              </h2>

              <p className="text-slate-600 dark:text-slate-300 text-sm leading-relaxed">
                {course.subtitle}
              </p>

              {/* Meta stats */}
              <div className="flex flex-wrap items-center gap-4 text-xs pt-2 text-slate-500 dark:text-slate-400 border-t border-slate-200 dark:border-slate-800/80">
                <div className="flex items-center gap-1.5 text-amber-500 dark:text-amber-400 font-bold">
                  <FiStar className="fill-amber-400" />
                  <span>{course.rating.toFixed(1)}</span>
                  <span className="text-slate-500 dark:text-slate-400 font-normal">({course.reviewsCount} reseñas)</span>
                </div>
                <div>👥 {course.studentsCount.toLocaleString()} estudiantes</div>
                <div className="flex items-center gap-1"><FiGlobe /> {course.language}</div>
                <div className="flex items-center gap-1"><FiClock /> Actualizado: {course.updatedAt}</div>
              </div>

              {/* What You Will Learn Card */}
              <div className="p-5 rounded-xl bg-slate-50 dark:bg-slate-950/60 border border-slate-200 dark:border-slate-800 space-y-3">
                <h4 className="text-sm font-bold text-slate-900 dark:text-white flex items-center gap-2">
                  <FiAward className="text-cyan-500 dark:text-cyan-400" /> Lo que aprenderás en este curso
                </h4>
                <div className="grid grid-cols-1 sm:grid-cols-2 gap-2.5 pt-2">
                  {course.whatYouWillLearn.map((item, idx) => (
                    <div key={idx} className="flex items-start gap-2 text-xs text-slate-700 dark:text-slate-300">
                      <FiCheckCircle className="text-emerald-500 dark:text-emerald-400 text-sm mt-0.5 shrink-0" />
                      <span>{item}</span>
                    </div>
                  ))}
                </div>
              </div>
            </div>

            {/* Video Preview & Buy Box */}
            <div className="lg:col-span-5 space-y-4">
              <div className="rounded-xl overflow-hidden bg-slate-950 border border-slate-800 shadow-xl relative aspect-video group">
                {!isPlayingVideo ? (
                  <>
                    <img
                      src={course.thumbnail}
                      alt={course.title}
                      className="w-full h-full object-cover"
                    />
                    <div className="absolute inset-0 bg-slate-950/40 flex flex-col items-center justify-center gap-2">
                      <button
                        onClick={() => setIsPlayingVideo(true)}
                        className="w-14 h-14 rounded-full bg-cyan-500 hover:bg-cyan-400 text-slate-950 flex items-center justify-center text-xl shadow-lg shadow-cyan-500/50 hover:scale-110 transition-transform"
                      >
                        <FiPlay className="ml-1" />
                      </button>
                      <span className="text-xs font-bold text-white bg-slate-900/80 px-2.5 py-1 rounded-md border border-slate-700">
                        Vista previa gratuita de lección
                      </span>
                    </div>
                  </>
                ) : (
                  <div className="w-full h-full flex flex-col items-center justify-center bg-slate-950 p-4 text-center space-y-3">
                    <div className="w-12 h-12 rounded-full bg-cyan-500/20 text-cyan-400 flex items-center justify-center text-xl animate-pulse">
                      <FiPlay />
                    </div>
                    <div>
                      <p className="text-xs font-bold text-white">Reproduciendo Clase Muestra (HD)</p>
                      <p className="text-[11px] text-slate-400">Lección 1: Novedades y Configuración Inicial</p>
                    </div>
                    <button
                      onClick={() => setIsPlayingVideo(false)}
                      className="text-xs text-rose-400 hover:underline"
                    >
                      Pausar y volver a portada
                    </button>
                  </div>
                )}
              </div>

              {/* Price & Checkout Card */}
              <div className="p-5 rounded-xl bg-slate-50 dark:bg-slate-950/80 border border-slate-200 dark:border-slate-800 space-y-4 shadow-xl">
                <div className="flex items-baseline justify-between">
                  <div className="flex items-baseline gap-2">
                    <span className="text-3xl font-black text-slate-900 dark:text-white font-mono">
                      ${course.price.toFixed(2)}
                    </span>
                    {course.originalPrice > course.price && (
                      <span className="text-sm text-slate-400 line-through font-mono">
                        ${course.originalPrice.toFixed(2)}
                      </span>
                    )}
                  </div>
                  {discountPercent > 0 && (
                    <span className="px-2 py-1 rounded bg-rose-500/20 border border-rose-500/30 text-rose-500 dark:text-rose-400 text-xs font-bold">
                      {discountPercent}% Descuento
                    </span>
                  )}
                </div>

                {/* If isTeacherPreview: Disable Buy & Cart buttons */}
                {isTeacherPreview ? (
                  <div className="space-y-2 pt-1">
                    <button
                      disabled
                      className="w-full py-3 bg-slate-200 dark:bg-slate-800 text-slate-500 dark:text-slate-400 font-bold rounded-xl text-xs border border-slate-300 dark:border-slate-700 cursor-not-allowed flex items-center justify-center gap-2 select-none"
                      title="Este curso pertenece a tu propia cuenta de instructor"
                    >
                      <FiLock className="text-sm" /> No puedes comprar tu propio curso
                    </button>

                    <button
                      disabled
                      className="w-full py-2.5 bg-slate-200/60 dark:bg-slate-800/60 text-slate-400 dark:text-slate-500 font-semibold rounded-xl text-xs border border-slate-300 dark:border-slate-800 cursor-not-allowed flex items-center justify-center gap-2 select-none"
                    >
                      <FiShoppingCart className="text-sm" /> Añadir al Carrito (Deshabilitado)
                    </button>
                  </div>
                ) : (
                  <div className="space-y-2">
                    <button
                      onClick={() => {
                        onBuyNow(course);
                        onClose();
                      }}
                      className="w-full py-3 bg-gradient-to-r from-emerald-600 to-teal-500 hover:from-emerald-500 hover:to-teal-400 text-white font-bold rounded-xl text-sm shadow-lg shadow-emerald-500/20 transition-all hover:scale-[1.01]"
                    >
                      Comprar Ahora
                    </button>

                    <button
                      onClick={() => onAddToCart(course)}
                      disabled={isInCart}
                      className={`w-full py-2.5 rounded-xl text-sm font-bold flex items-center justify-center gap-2 transition-all ${
                        isInCart
                          ? 'bg-slate-200 dark:bg-slate-800 text-slate-400 dark:text-slate-400 border border-slate-300 dark:border-slate-700 cursor-default'
                          : 'bg-slate-900 dark:bg-slate-800 hover:bg-slate-800 dark:hover:bg-slate-700 text-white border border-slate-800 dark:border-slate-700'
                      }`}
                    >
                      <FiShoppingCart />
                      <span>{isInCart ? 'Ya está en el carrito' : 'Añadir al Carrito'}</span>
                    </button>
                  </div>
                )}

                <div className="space-y-1.5 text-[11px] text-slate-500 dark:text-slate-400 pt-2 border-t border-slate-200 dark:border-slate-800">
                  <div className="flex items-center gap-2">
                    <FiClock className="text-cyan-500 dark:text-cyan-400" /> {course.duration} de video bajo demanda
                  </div>
                  <div className="flex items-center gap-2">
                    <FiBook className="text-cyan-500 dark:text-cyan-400" /> {course.lessonsCount} lecciones descargables
                  </div>
                  <div className="flex items-center gap-2">
                    <FiShield className="text-emerald-500 dark:text-emerald-400" /> Garantía de 30 días o te devolvemos el dinero
                  </div>
                  <div className="flex items-center gap-2">
                    <FiAward className="text-cyan-500 dark:text-cyan-400" /> Certificado de acreditación oficial
                  </div>
                </div>
              </div>
            </div>

          </div>

          {/* Nav Tabs inside modal */}
          <div className="border-b border-slate-200 dark:border-slate-800 flex gap-6 text-sm font-semibold">
            <button
              onClick={() => setActiveTab('curriculum')}
              className={`pb-3 transition relative ${
                activeTab === 'curriculum'
                  ? 'text-cyan-600 dark:text-cyan-400 border-b-2 border-cyan-500'
                  : 'text-slate-500 dark:text-slate-400 hover:text-slate-900 dark:hover:text-slate-200'
              }`}
            >
              Contenido del Curso ({course.modules.length} Módulos)
            </button>
            <button
              onClick={() => setActiveTab('instructor')}
              className={`pb-3 transition relative ${
                activeTab === 'instructor'
                  ? 'text-cyan-600 dark:text-cyan-400 border-b-2 border-cyan-500'
                  : 'text-slate-500 dark:text-slate-400 hover:text-slate-900 dark:hover:text-slate-200'
              }`}
            >
              Instructor
            </button>
            <button
              onClick={() => setActiveTab('reviews')}
              className={`pb-3 transition relative ${
                activeTab === 'reviews'
                  ? 'text-cyan-600 dark:text-cyan-400 border-b-2 border-cyan-500'
                  : 'text-slate-500 dark:text-slate-400 hover:text-slate-900 dark:hover:text-slate-200'
              }`}
            >
              Valoraciones ({course.reviews.length})
            </button>
          </div>

          {/* Tab Content 1: Curriculum */}
          {activeTab === 'curriculum' && (
            <div className="space-y-4">
              <div className="flex items-center justify-between text-xs text-slate-500 dark:text-slate-400">
                <span>{course.modules.length} módulos • {course.lessonsCount} lecciones • {course.duration} duración total</span>
              </div>

              <div className="space-y-3">
                {course.modules.map((mod) => {
                  const isExpanded = !!expandedModules[mod.id];
                  return (
                    <div key={mod.id} className="rounded-xl border border-slate-200 dark:border-slate-800 overflow-hidden bg-slate-50 dark:bg-slate-950/40">
                      <button
                        onClick={() => toggleModule(mod.id)}
                        className="w-full flex items-center justify-between p-4 bg-slate-100 dark:bg-slate-900/60 hover:bg-slate-200 dark:hover:bg-slate-900 transition text-left"
                      >
                        <div className="font-bold text-sm text-slate-800 dark:text-slate-200 flex items-center gap-2">
                          {isExpanded ? <FiChevronUp className="text-cyan-500 dark:text-cyan-400" /> : <FiChevronDown className="text-slate-400 dark:text-slate-500" />}
                          <span>{mod.title}</span>
                        </div>
                        <span className="text-xs text-slate-500 dark:text-slate-400 font-mono">
                          {mod.lessons.length} lecciones
                        </span>
                      </button>

                      {isExpanded && (
                        <div className="divide-y divide-slate-200 dark:divide-slate-800 p-2 space-y-1">
                          {mod.lessons.map((lesson) => (
                            <div
                              key={lesson.id}
                              className="flex items-center justify-between p-2.5 rounded-lg hover:bg-slate-100 dark:hover:bg-slate-900/80 text-xs transition"
                            >
                              <div className="flex items-center gap-2.5 text-slate-700 dark:text-slate-300">
                                <div className="w-5 h-5 rounded-full bg-slate-200 dark:bg-slate-800 text-slate-500 dark:text-slate-400 flex items-center justify-center text-[10px]">
                                  <FiPlay />
                                </div>
                                <span>{lesson.title}</span>
                              </div>

                              <div className="flex items-center gap-3">
                                {lesson.isFreePreview && (
                                  <span className="px-2 py-0.5 rounded bg-cyan-500/20 text-cyan-700 dark:text-cyan-300 border border-cyan-500/30 text-[10px] font-bold">
                                    Vista Previa
                                  </span>
                                )}
                                <span className="text-slate-500 dark:text-slate-400 font-mono">{lesson.duration}</span>
                              </div>
                            </div>
                          ))}
                        </div>
                      )}
                    </div>
                  );
                })}
              </div>
            </div>
          )}

          {/* Tab Content 2: Instructor */}
          {activeTab === 'instructor' && (
            <div className="p-6 rounded-xl bg-slate-50 dark:bg-slate-950/60 border border-slate-200 dark:border-slate-800 space-y-4">
              <div className="flex flex-col sm:flex-row items-start sm:items-center gap-4">
                <img
                  src={course.instructor.avatar}
                  alt={course.instructor.name}
                  className="w-16 h-16 rounded-full object-cover ring-2 ring-cyan-500/50"
                />
                <div>
                  <h3 className="text-lg font-bold text-slate-900 dark:text-white">{course.instructor.name}</h3>
                  <p className="text-xs text-cyan-600 dark:text-cyan-400 font-medium">{course.instructor.role}</p>
                  
                  <div className="flex items-center gap-4 text-xs text-slate-500 dark:text-slate-400 mt-2">
                    <span className="flex items-center gap-1 text-amber-500 dark:text-amber-400 font-bold">
                      <FiStar className="fill-amber-400" /> {course.instructor.rating} Calificación
                    </span>
                    <span>👨‍🎓 {course.instructor.totalStudents.toLocaleString()} Estudiantes</span>
                    <span>📚 {course.instructor.totalCourses} Cursos creados</span>
                  </div>
                </div>
              </div>

              <p className="text-xs text-slate-700 dark:text-slate-300 leading-relaxed border-t border-slate-200 dark:border-slate-800 pt-4">
                {course.instructor.bio}
              </p>
            </div>
          )}

          {/* Tab Content 3: Reviews */}
          {activeTab === 'reviews' && (
            <div className="space-y-4">
              {course.reviews.map((rev) => (
                <div key={rev.id} className="p-4 rounded-xl bg-slate-50 dark:bg-slate-950/60 border border-slate-200 dark:border-slate-800 space-y-2">
                  <div className="flex items-center justify-between">
                    <div className="flex items-center gap-2.5">
                      <img
                        src={rev.userAvatar}
                        alt={rev.userName}
                        className="w-8 h-8 rounded-full object-cover"
                      />
                      <div>
                        <h4 className="text-xs font-bold text-slate-900 dark:text-white">{rev.userName}</h4>
                        <span className="text-[10px] text-slate-500">{rev.date}</span>
                      </div>
                    </div>

                    <div className="flex text-amber-400 text-xs">
                      {[...Array(rev.rating)].map((_, i) => (
                        <FiStar key={i} className="fill-amber-400" />
                      ))}
                    </div>
                  </div>

                  <p className="text-xs text-slate-700 dark:text-slate-300 leading-relaxed pl-10">
                    "{rev.comment}"
                  </p>
                </div>
              ))}
            </div>
          )}

        </div>

      </div>
    </div>
  );
};